Due to aging of the society, there has been a high demand for a disposal box for diapers and the like in proportion with the population who need nursing care. However, the offensive odor that is released every time the box is opened gives discomfort or a burden to a caregiver and the ambient, and also it is unsanitary. Further, although garbage storage boxes are present in homes and restaurants, since offensive odor caused by growth of bacteria is released every time the boxes are opened, a burden on relevant workers such as housewives is large. As the use of garbage disposer increases due to the development of biotechnology, offensive odor released around the garbage disposer during operation has become a very serious problem. In addition, transportation by transport containers, trucks, and the like are mainly used for foreign/domestic distribution of refrigerated/normal-temperature products, and the like, and there are a number of marine containers/on-land containers/container-type trucks and the like equipped with air conditioners. However, residual odor of loaded products and musty odor in air conditioners have become problematic. Further, air conditioners for storehouses, refrigerators, or indoor/in-vehicle spaces have the problem of offensive odor depending on the usage conditions including stored materials.
As a solution to the above problem, a simplified sterilizer/deodorizer, such as a spray type, has been proposed in the past. However, when such a simplified sterilizer/deodorizer is used in a waste box or a garbage storage box, offensive odor is released when the box is opened. Further, when it is used in an air conditioner (as, for example, dispersive or cyclic sterilization system), the problem is that there is a region, in an air conditioner, incapable of being cleaned; or abnormal odor and musty odor left after cleaning migrate to subsequently loaded products. In addition, as another solution technique, a method of suctioning air from a sterilizing/deodorizing target space and adsorbing or removing contaminated materials by a filter, or an expensive catalyst that removes offensive odor has been proposed. However, maintenance such as replacement of a filter is necessary for long-term use. In addition, in many cases, satisfactory performance may not be obtained because the performance of a filter is insufficient. Even when the filter performance is good, a large and expensive catalyst body and a high maintenance cost are required in many cases.
However, recently, air cleaners and air conditioners for generating negative ions or ozone for cleaning and refreshing indoor air have been introduced. There have been proposed a plurality of technologies for deodorizing a target space by using a negative ion/ozone generation device that simultaneously generates negative ions and ozone that have a deodorizing effect.
First, a negative ion/ozone generation device according to Patent Literature 1 is designed to be installed on a ceiling of a room and is configured such that a positive electrode is located beneath a negative electrode. According to this configuration, a downstream airflow containing negative ions and ozone can be generated even without using a fan or a motor.
Next, a negative ion/ozone generation device according to Patent Literature 2 includes a cathode electrode having a needle-shaped tip and a cylindrical ground electrode that is concentrically installed in parallel to the cathode electrode, in which the cathode electrode and the ground electrode are relatively movable. A high voltage is applied to the cathode electrode to adjust the distance between the tip portion of the cathode electrode and the end of the ground electrode, thereby generating negative ions or ozone.
Next, a negative ion/ozone generation device according to Patent Literature 3 applies a high direct voltage between a needle-shaped electrode and an earth electrode to generate corona discharge at the apical portion of the needle-shaped electrode, thereby generating ozone or negative ions.
Next, a negative ion/ozone generation device according to Patent Literature 4 includes a positive electrode consisting of a metal plate having one or more holes with an erected portion therearound, and a negative electrode having a tip located adjacent to the holes of the positive electrode. With this configuration, since a sufficient airflow is generated by discharge, an air stream capable of diffusing generated negative ions or ozone in a space can be generated even without using a separate blower device such as a fan or a pump.
The inventions according to the Patent Literatures 1 to 4 describe generating ions and ozone and applying the same to a target object. However, these technologies, for example, assume that the device is placed in a sterilizing/deodorizing target space, such as inside of a trashcan, and performs discharge. For example, if in a trash can, an organic matter releasing offensive odor may be resolved by microorganisms to generate flammable gas such as methane gas. When discharge is performed in this state, fire or explosion may occur due to the generation of spark.
Thus, in order to remove such a danger, research is being conducted to develop an external sterilizing/deodorizing device that performs discharge outside a space of a target object, generates ions and ozone, and introduces the generated materials into the space in which the target object is placed (Patent Literature 5).
Further, in an air cleaner according to Patent Literature 6, a plurality of needle-shaped electrodes and planar collector electrodes are arranged. However, since this technique intends to generate ions, if ion “wind” is generated, the force of the ion wind is not considered. Accordingly, as described in the Patent Literature 6 (in particular, FIGS. 1 and 2), if the electrodes are significantly separated from each other, when the ion wind is generated, the wind force is significantly reduced, so that there is a problem that the ion wind is less likely to reach a target object.
Further, Patent Literatures 7 to 9 each describe a device for generating ion wind using a needle-shaped electrode and a planar opposite electrode. However, in those techniques, there is a problem that the force of the generated ion wind is insufficient from a practical viewpoint.
Further, Patent Literatures 10 and 11 describe an ion wind generation device in which arranged needle-shaped electrodes and cylindrical opposite electrodes are arranged. However, if the opposite electrode has a cylindrical shape as with those techniques, there is a problem that the force of the generated ion wind is insufficient from a practical viewpoint even if a plurality of electrodes are combined.
Furthermore, Patent Literature 12 discloses the technique of forming an opposite electrode into not a cylindrical shape but a plate shape for ease of cleaning. However, the technique disclosed in the Patent Literature 12 has a problem that the force of generated ion wind is insufficient from a practical viewpoint as with the Patent Literatures 7 to 9.